I think I got it figured out. Did just like Patrick said... converted my spline model to a vertex model, selected the faces on the two "sides" and created a new shading domain, then set up a layers list shader (this is what took me the longest to figure out how to get right). Now, of course, there's no visible joint at the corners where the two "pieces" would have been mitered together, but at least the grain is going in the proper directions... and perhaps the maker of this particular frame had some laser guided, diamond tipped miter saw and the joints are just soooo perfect that they're practically invisible... :) Thanks for the help Patrick.